Gun for caseless ammunition in which a slidable sleeve defines the chamber



Inventor Eugene M. Stoner Port Clinton, Ohio 136,705

June 13, 1968 Dec. 15, 1970 TRW Inc.

Cleveland, Ohio a corporation of Ohio App]. No. Filed Patented Assignee GUN FOR CASELESS AMMUNITION IN WHICH A SLIDABLE SLEEVE DEFINES THE CHAMBER 16 Claims, 8 Drawing Figs.

U.S. Cl 89/156, 42/32.5: 89/17. 89/26. 89/33: 102/38 Int. Cl F4ld 9/02 Field olSearch 42/2, 39.5, 10; 89/7, 17, 26, 33MC,155, 156

References Cited UNITED STATES PATENTS 111 6/1921 Hall et a1. 89/7 1,856,022 4/1932 Blacker 89/7UX 2,353,601 7/1944 Tisdale 89/156X 3,008.258 11/1961 Johnson 89/26X 14,253 2/1856 Robertson et a1 42/10 2,480,100 8/1949 Weiss et a1 89/26X FOREIGN PATENTS 560,813 4/1944 Great Britain 89/7 Primary Examiner-Benjamin A. Borchelt Assistant Examiner-Stephen C. Bentley Attorney-Hill, Sherman, Meroni, Gross and Simpson ABSTRACT: An automatic gun for use in connection with caseless ammunition, which has a standing breech encircled by a sleeve slidable along the breech to a position between the breech and the end of the gun barrel to define a firing chamber area. The end of the barrel has an extension extending into the front of the sleeve and expandable therein to provide obturation at the front of the firing chamber and the end of the breech has a scalloped area extending into the rear of the sleeve allowing expansion of the breech to provide obturation at the back of the firing chamber.

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GUN FOR CASELESS AMMUNITION IN WHICH A SLIDABLE SLEEVE DEFINES THE CHAMBER BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to armaments and more particularly to a standing breech gun adapted to repetitively fire caseless ammunition.

2. Prior Art Automatic guns usually utilize ammunition having a propellant filled metal or plastic casing behind a projectile. More recently, ammunition has been developed which utilizes molded propellant either behind or surrounding a projectile, and which does not utilize a metallic or plastic casing. While such molded propellant caseless ammunition can be fired from a gun having an integral firing chamber, because of the nature of the molded propellant, it is extremely difficult to remove misfired cartridges from the firing chamber.

SUMMARY My invention overcomes this difficulty, and provides a novel concept utilizing a slidable sleeve to provide a firing chamber between the end of a gun barrel and a standing breech.

The gun is fired from the sleeve-open position with the sleeve retracted around a cylindrical standing breech which contains a firing pin. As the sleeve begins to move forward towards the end of the barrel, a caseless shell is in-fed to the gun between the breech and the end of-the barrel. The sleeve then continues forward, enveloping the caseless shell and holding it between the breech and the end of the barrel. With the sleeve in its full-forward position, it defines a firing chamber area between the breech and the barrel end. With the sleeve in this position, the cartridge is fired. The recoil of the gun is utilized to return the sleeve to' its sleeve-open position.

In order to provide for obturation or sealing of the propellant gases, the breech end of the barrel-has a thin-walled cylindrical section which extends into the sleeve-During firing of the shell, the propellant gases expand'this thin-walled barrel section into tight sealing relationship with the. inner diameter of the sleeve.

Obturation at the breech end of the sleeveis provided for in the same manner by a circumferential scallop or groove cut into the end face of the breech near the outer diameter thereof. Since the breech extends into the sleeve, the thin periphery of the breech created by the scallop is expanded into sealing engagement with the inner diameter of the sleeve by the propellant gases. Such a scallop may also be provided in the firing pin to create a seal between it and the breech.

It is thus an object of this inventionto provide a standing breech gun capable of firing caseless ammunition.

It is another object of this invention to provide a gun capable of firing caseless ammunition which utilizes a sliding cylindrical sleeve to define a firing chamber between the breech end of the barrel and a standing breech;

It is a further object of this invention to provide a gun capable of repetitive fire of caseless ammunition while providing access to the firing chamber for removal ofmisfired ammunition.

It is a further and more specific object of this invention to provide a gun capable of repetitive firing of caseless ammunition which utilizes a spring-loaded recoil operated slidable sleeve to define a firing chamber between a standing breech and the breech end of the barrel which has a thin-walled cylindrical extension of the barrel extending intothe front of the sleeve to provide for expansion obturation at the front of the firing chamber and a thin-walled area of the standing breech extending into-the rear of the sleeve to provide obturation at the rear of the firing area.

Other and further objects of this invention will be apparent to those skilled in this art from the following detailed description of the annexed sheets of drawings which, by way of a preferred embodiment of the invention, illustrate one example of the invention.

FIG. 1 is a perspective view of an automatic gun embodying this invention.

FIG. 2 is a longitudinal cross-sectional view of a caseless ammunition round.

FIG. 3 is a fragmentary view of the barrel extension, standing breech, sleeve and operating rod assemblies of this invention.

FIG. 4 is a fragmentary longitudinal cross-sectional view of the gun, illustrating the standing breech, the breech end of the barrel, and the slidable sleeve of this invention.

FIG. 5 is a fragmentary, cross-sectional view taken along the lines V-V ofFIG. 4.

FIG. 6 is a fragmentary cross-sectional view similar to FIG. 4, illustrating partial closing of the sleeve.

FIG. 7 is a fragmentary cross-sectional view similar to FIG. 6, illustrating the fully-closed firing position of the sleeve.

FIG. 8 is a fragmentary cross-sectional view similar to FIG. 7 but on a larger scale, illustrating the manner in which the sleeve of this invention is sealed. 1

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 illustrates generally an automatic gun 10 adapted to fire caseless ammunition ll stored in linked holders 12.

The gun 10 consists generally of a barrel l3 and a housing 14 which covers the rearmost portion of the barrel l3 and which houses a barrel extension and breech assembly. Cartridge feed devices 15 feed the cartridges 11 into the firing chamber of the gun 10. An access opening I6 is provided through the top of the gun 10 to remove misfired cartridges.

FIG. 2 illustrates a type of caseless cartridge 11 which consists of molded propellant I7 in which a projectile 18 is embedded. At the rear of the projectile 18, a quick fire propellant 19 is provided. The quick fire propellant l9 ignites and burns faster than the remainder of the propellant 17, thus giving an initial push to the projectile 18. Primer propellant 20 is used to initiate firing of the shell 11.

FIG. 3 illustrates the components which are positioned within the housing 14 and specifically a barrel extension 21 which surrounds the breech end of thebarrel l3 and extends back therefrom to terminate in a standing breech assembly 22 from which projects interiorly of the barrel extension the cylindrical standing breech 25. It is to be understood that whenever I refer to a standing breech, I am referring to an element such as the element 25 which closes the breech end of the firing chamber and which does not move with respect to the breech end of the barrel during operation of the gun mechanism. Encircling a portion of the standing breech 25 and extending between it and the breech end 26 of the barrel 13 is a cylindrical sleeve 27. The sleeve 27 can reciprocally slide back and forth over the standing breech 25. The movement of the breech 27 is actuated by a control rod 28 connected to the sleeve 27 through an interfitting connection 29. The operating rod 28 is free to slide back and forth below the barrel extension 21. This movement of the operating rod 28 carries the sleeve 27 back and forth around the standing breech 25. The operating rod 28 is spring loaded toward the barrel 13 and is recoil operated toward the standing breech as sembly 24.

FIG. 4 illustrates, in cross section, the sleeve mechanism of this invention. The barrel 13 extends into the barrel extension 2! forward of the end 30 of the cylindrical standing breech 25. The barrel 13 has a reduced-diameter end portion 31 integral with the main body 32 through a frustoconical portion 33. An axial bore 34 of the barrel, whichmay be rifled, terminates in a frustoconically flared-out portion 35 at the end wall 36 of the reduced diameter portion 31.

The breech assembly 24 is secured to the barrel extension 21 by means of an interrupted thread screw 37. The breech assembly 24 consists of a back plate cap 38 which is screwed on to the barrel extension and the cylindrical standing breech portion 25 which extends axially forward from the cap 38. The standing breech 25 has an axial bore 39 which receives a cylindrical firing pin 40. The firing pin 40 is loaded away from the front 30.0f the standing breech by a spring 41 fitted in a larger diameter portion 42 of the axial bore 39 at the rear thereof.

I The barrel extension 21 has an opening 45 at the top thereof between the end 36 of the barrel and the end 30 of the standing breech. The opening 45 cooperates with the opening 16 in the housing 14 to allow removal of misfired cartridges. A bottom opening 46 accommodates the movement of the connection 29. Side openings 47 provide for'infeed of the cartridges to the firing area.

\ The firing area 48 is that area between the breech end 36 of the reduced diameter barrel extension 31 and the end 30 of the standing breech 25 which is encircled by the slidable sleeve 27. when in its firing position. The sleeve 27 is illustrated in FIG: 4 in its seared or full-open position. The sleeve 27 is cylindrical with an axial bore 49 having the same diameter as the diameter of the standing breech 25. A frustoconical taper 50 of the bore 49 extends outwardly from the main portion of the bore 49 to the front end 51 of the sleeve. The taper 50' of the bore 49 is designed to mate with the taper of the frustoconical portion 33 of the barrel 13. I

4 A reduced-diameter midportion 52 provides scraping edges 53around the outer diameter of the sleeve 27. The scraping edges 53 scrape the inner diameter 54 of the barrel extension 21 when the sleeve 27 reciprocates back and forth, thus clearing the inner face 54 of any deposits which might otherwise build up thereon from the ignition of the propellant powder of the caseless ammunition. The front end 30 of the standing breech 25 at its outer periphery provides a circular scraping edge 55 which scrapes the bore 49 of the sleeve 27 when the sleeve is recoiled rearwardly towards its seared position.

Buffer springs 56 bottoming against the cap 38 of the standing breech assembly 24 provide a backstop for the sleeve 27 to arrest its rearward motion during recoil of the gun. The sleeve 27 has a projecting finger 57 on the exterior thereof which extends through the opening 46 in the barrel extension 21 to interfit with a slot 58 on the top of the control rod 28 to provide theconnection 29. In its full-open or-seared position shown in FIG. 4, the drive spring 59 of the control rod 28 is in a compressed position. Releasing the gun sear mechanism (not shown) allows the control rod 28 to be driven forward by the action of the spring 59. The forward motion of the control rod carries the sleeve 27 forward towards the barrel 13.

As shown in FIG 5, as the sleeve 27 begins to move forward, a cartridge 11"is in-fed through one of the side openings 45 intoposition between the end 36 of the barrel 13 and the end 30 of the standing breech 25. The infeed of the cartridge 11 may be by any type of feed mechanism 60 which will strip the cartridge 11 from the link. 12 and push it through the opening 45'into position. It is of course to be understood that cartridge feed apparatus using other than link-held cartridges can be used in connection with this invention.

As shown in FIG. 6, after the cartridge 11 has been placed within the firing area 48 by the loading mechanism 60, the

I sleeve 27 continues to move forward carried by the springloaded movement of the operatingrod 28. The frustoconical bore 50 of the front 51 of the sleeve accommodates a certain amount of misalignment of the cartridge 11 with the central bore 49 of the sleeve. At this point the sleeve begins to encir- 3 cle the cartridge.

FIG. 7illustrates the fully-closed or firing position of the sleeve 27 when its frontwall 51 has mated with the barrel 13 and the reduced-diameter portion 31 of the barrel is interior of the central bore 49 of the sleeve 27. When the sleeve 27 has reached this position, the barrel extension 21 is also in its fullforward position and the openings 45 and 16 are aligned. At thispoint, the cartridge 11 can be fired by the firing pin 40. If the cartridge 11' fails to fire-when struck with the firing pin, the operating rod 28 can bedrawn back thus causing the sleeve 27 to slide rearward over the standing breech 25. This gives access to the misfired cartridge 11 through the openings 16 and 45 to remove the cartridge.

When the cartridge 11 is fired, the recoil created by the reaction of the propellant gases against the standing breech assembly will cause the barrel extension 21 to move rearward at a high speed. The'rearward movement'of the barrel extension 21 will carry the sleeve 27 and operating rod 28 in a rearward direction. Abruptly arresting the motionof the barrel extension 21 causes the sleeve 27. tocontinue its movement backward within the barrel extension until it strikes the buffer springs 56. This rearward movement again compresses the spring 59 in the control rod 28 and returns the mechanism to the position illustrated in FIG. 4. During rearward movement of the sleeve, the interior periphery of the sleeve 27 is scraped by the edge 55 of the front end 30 of the standing breech and the walls of the barrel extension 21 are scraped by the edges 53 on the outer diameter of the sleeve 23, thus preventing fouling of the gun dueto gunpowder buildup.

During firing of the cartridge 11, extremely high pressures are created by the burning of the propellant. It is desirable that these pressures be contained within the firing chamber and barrel in order to accelerate the projectile to the greatest possible speed. Additionally, because of the extreme pressures and the fast movement of the gases, if the gases are allowed to escape, they can erode the gun mechanism in the areaof escape. For this reason, it is desirable to assure maximum obturation of the firing chamber.

FIG. 8 illustrates the novel sealing concept of my invention. As has been described, the reduced diameter portion 31 of the barrel 13 extends interiorly of the sleeve 27 into the central bore 49 thereof. As the projectile 18 is fired forward into the bore 34 of the barrel 13, the gas pressures behind the projectile 18 cause the thin-walled reduced-diameter portion 31 of the barrel to radially expand into tight sealing engagement between the outer diameter of the portion 31 and the inner diameter 49 of the sleeve 27, thus preventing propellant gas escape at the front of the sleeve.

Obturation at the rear of the sleeve is accomplished in the same manner. An annular scallop 66 is cut into the end 30 of the standing breech 25. The scallop 66 is located close to the outer diameter 67 of the standing breech and provides an annular thin wall 68 adjacent the inner diameter 49 of the sleeve. Propellant gasses act in the scallop 66 in the same manner as they act on the reduced-diameter portion 31 to spread the thin-walled portion 68 into circumferential sealing engagement with the inner diameters 49 of the sleeve 27. A scallop 69 like the scallop 66 may also be provided in the end 70 of the firing pin 40 to provide for expansion sealing of the bore 39 of the standing breech.

Secondary seals may also be utilized to aid in the effectiveness of the primary expansion seals. A substantially U-shaped low-pressure spreading leg seal 71 can be used in connection with the front end obturation. The seal 71 fits in an increased diameter internal groove 72 in the sleeve 27 which is closed by a threaded plug 73 which forms the-inner diameter portion of the front 51 of the sleeve 27. The low-pressure seal 71 is placed in the groove 72 with its bight bottoming against the plug 73. As gases enter into the open channel 74 of the seal 71, the legs 75 and 76 are spread apart to provide the seal. The low-pressure seal 71 allows sufficient pressure build up to insure the expansion of the reduced diameter portion 31 of the barrel 13.

A second low-pressure seal 77 of the same design as the seal tion 80 contains an axial bore 810 receiving the firing pin 40.

Additionally, a larger diameter axial bore 82 at the base of the end portion 80 can receive an O-ring seal 83 which cooperates with the scallop 69 in the firing pin to aid in sealing the firing pin receiving bores in the standing' breech 25.

It can therefore be seen from the above description of a preferred embodiment that my invention provides for a novel gun capable of firing caseless'ammunition which incorporates a slidable sleeve to define a firingchamber between the standing breech and the breech end of the barrel. The breech end of the barrel has a reduced diameter extension extending into the interior diameter of the sleeve to provide obturation of the front end of the sleeve. Scallops in the front end of the breech provide for expansion obturation at the rear of the sleeve. Although my invention has been described above in connection with a gun designed to fire caseless ammunition, it is to be understood that the teachings of my invention are equally adaptable to guns firing conventional cased ammunition. Although the teachings of my invention have herein been discussed with reference to specific theories and embodimerits, it is to be understood that these are by way of illustration only and that others may wish-to utilize my invention in different designs or applications.

lclaim:

l. A gun for firing caseless ammunition which comprises: a barrel and a standing breech in axially spaced relation providing a firing space gap therebetween, a cylindrical sleeve having both ends open movable to encircle said firing space, a portion of the standing breech projecting into one end of said sleeve at all operating positions of said sleeve and terminating in spaced relation to said barrel, and the other end of the sleeve adapted to mate with an end of the barrel, said firing space dimensioned to receive the entirety of a caseless ammunition round therein. I

2. in a gun for firing caseless ammunition, theimprovement of a firing chamber between the breech end of the gun barrel and a standing breech defined by a movable open ended cylindrical sleeve, a portion of said standing breech projecting into said sleeve at all operating positions of said sleeve, said firing chamber dimensioned to receive the entirety of an ammunition round consisting of a projectile and propellant therein.

3. In a gun assembly comprising; a cylindrical standing breech member having a percussion firing pin therethrough, a gun barrel having an end spaced from the said standing breech, a sleeve adapted to span the space between the said end of the said barrel and the said standing breech, the said sleeve being movable toward and away from the said end of the said barrel, and end portion of said member projecting into said sleeve at all operating positions of said sleeve, and the said sleeve adapted to define a firing chamber therein.

4. The gun assembly of claim 3 wherein the said sleeve is adapted to move towards and away from the said end of the said barrel while encircling portions of the said standing breech member, said firing chamber dimensioned to receive the entirety of a caseless ammunition round including propellant and projectile.

5. A gun for firing caseless ammunition which comprises: a gun barrel having a projectile-receiving end, a cylindrical standing breech member having a firing end, said ends aligned with and spaced from each other, a sleeve adapted to encircle portions of said cylindrical standing breech member, said sleeve movable towards and away from said projectile-receiving end while remaining in encircling relationship with portions of said cylindrical standingbreech member, said sleeve adapted to span the space between the said ends, said sleeve adapted to define a firing chamber between said ends when spanning said space, said firing chamber dimensioned to receive the entirety of a caseless ammunition round without the projectile of said round extending beyond said firing chamber.

6. The gun of claim 5 wherein the said gun barrel has a reduced-diameter portion of the said projectile-receiving end adapted to extend interiorly of the said sleeve when the said sleeve is spanning the said space.

7. The gun of claim 6 wherein a portion of the firing end of the said cylindrical standing breech extends interiorly of the said sleeve when said sleeve is positioned to span the said space.

8. The gun of claim 7 wherein the said reduced-diameter portion of the said projectile-receiving end is adapted to radially expand into tight sealing engagement with a portion of the interior diameter of the said sleeve during firing of the said gun.

9. The gun of claim 8 wherein the said portion of the said firing end has a circumferential portion adapted to expand into sealing engagement with the interior diameter of the said sleeve during firing of the said gun.

10. A gun adapted to fire caseless ammunition which comprises: a gun barrel having a projectile-receiving bore therein, a standing breech assembly having an elongated cylindrical portion with an end aligned with and spaced from an end of the said barrel, a cylindrical hollow sleeve having both ends open adapted to encircle portions of the said cylindrical portion of the breech assembly, said sleeve adapted to reciprocally move along portions of said portion of said breech assembly, and end portion of said breech assembly projecting within said sleeve at all operating positions of said sleeve, said sleeve adapted to span the space between the said end of the standing breech assembly and the said end of the said barrel while an end portion of the said breech assembly remains interior of the said sleeve, the said cylindrical portion of the said breech assembly having a diameter substantially the same as the inner diameter of the said sleeve, a reduced diameter cylindrical extension Ion the end of the said gun barrel adapted to extend interiorly of the said sleeve when the said sleeve is spanning the said space, said reduced-diameter portion having an exterior diameter substantially the same as the inner diameter of the said sleeve, the said reduced-diameter portion adapted to radially expand under pressure during the firing of the said gun into tight circumferential sealing engagement with the inner diameter of the said sleeve, the said end portion of the said standing breech assembly having a circular groove therein spaced from the periphery thereof to create a thinwalled periphery around the said end, said thin-walled periphery adapted to expand under pressure during the firing of the gun into circumferential sealing engagement with the inner diameter of the said sleeve, and the said bore of the said gun being coaxial with the said end portion of the said stand breech assembly, the sleeve and the reduced-diameter portion, and the said space between the said end of the said breech assembly and the said end of the said barrel encircled by the said sleeve dimensioned toreceive the entirety of a caseless ammunition round including the projectile.

11. The gun of claim 10 wherein the said end of the said portion of the said standing breech assembly is adapted to scrape the inner diameter of the said sleeve when the said sleeve is reciprocated along the said standing breech assembly.

12. The gun of claim 10 wherein the said cylindrical portion of the said standing breech assembly has an axial bore therethrough, a firing pin in said bore having an end adapted to fire a cartridge, said end having a. circular groove therein, said groove providing a peripheral thin-walled area around the said end of the said firing pin, and the said thinwalled peripheral area adapted to expand into sealing engagement with the said bore.

13. A gun assembly comprising: a gun barrel with a projectile-receiving bore therethrough, a breech assembly having a percussion cartridge firing means therein, means for defining and enclosing a firing chamber between an end of the barrel and an end of the breech assembly, the said firing chamber dimensioned to receive the entirety of an ammunition round including the projectile thereof, the said projectile being fired while positioned within the said firing chamber, means actuated by pressures developed during operation of the assembly for sealing the said chamber except through the said bore, said means for defining and enclosing movable between open-firing chamber and closed-firing-chamber positions, means for moving the means for defining and enclosing, and an end portion of said breech assembly projecting into the said means for defining and enclosing at all operating positions of'the said means for defining and enclosing.

14. The assembly of claim 13 wherein the said'means for defining and enclosing comprises a hollow cylindrical sleeve movable along portions of the said breech assembly.

15. The assembly of claim 13 wherein thesaid means for moving the means for defining and enclosing includes a reciprocally movable operating rod spring-loaded in the direction of the said barrel and movable away from the said barrel by recoil pressures developed by the firing of the said gun assembly, the said operating rod operatively connected to the said means for defining and enclosing and the said recoil movement acting to compress a loading spring to spring-load the said operating rod.

the interior of the said means for defining and enclosing'dunv ing movement of the said means for definingand enclosing, and an end portion of said breech assembly projecting into the said means for defining and enclosing at all operating positions of the said means for defining and enclosing; V c t 

